Borderou de evaluare (job #349999)

Eroare de compilare: user.cpp: In function ‘int main()’: user.cpp:14:5: error: no match for ‘operator>’ in ‘std::cin > a’ user.cpp:14:5: note: candidates are: /usr/include/c++/4.6/bits/stl_pair.h:220:5: note: template<class _T1, class _T2> constexpr bool std::operator>(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&) /usr/include/c++/4.6/bits/stl_iterator.h:303:5: note: template<class _Iterator> bool std::operator>(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_Iterator>&) /usr/include/c++/4.6/bits/stl_iterator.h:353:5: note: template<class _IteratorL, class _IteratorR> bool std::operator>(const std::reverse_iterator<_IteratorL>&, const std::reverse_iterator<_IteratorR>&) /usr/include/c++/4.6/bits/stl_iterator.h:1073:5: note: template<class _IteratorL, class _IteratorR> bool std::operator>(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorR>&) /usr/include/c++/4.6/bits/stl_iterator.h:1079:5: note: template<class _Iterator> bool std::operator>(const std::move_iterator<_Iterator>&, const std::move_iterator<_Iterator>&) /usr/include/c++/4.6/bits/basic_string.h:2547:5: note: template<class _CharT, class _Traits, class _Alloc> bool std::operator>(const std::basic_string<_CharT, _Traits, _Alloc>&, const std::basic_string<_CharT, _Traits, _Alloc>&) /usr/include/c++/4.6/bits/basic_string.h:2559:5: note: template<class _CharT, class _Traits, class _Alloc> bool std::operator>(const std::basic_string<_CharT, _Traits, _Alloc>&, const _CharT*) /usr/include/c++/4.6/bits/basic_string.h:2571:5: note: template<class _CharT, class _Traits, class _Alloc> bool std::operator>(const _CharT*, const std::basic_string<_CharT, _Traits, _Alloc>&) user.cpp:9:26: warning: unused variable ‘vv’ [-Wunused-variable] user.cpp:9:29: warning: unused variable ‘j’ [-Wunused-variable] user.cpp:13:7: warning: unused variable ‘b’ [-Wunused-variable] user.cpp:13:9: warning: unused variable ‘c’ [-Wunused-variable] user.cpp:13:11: warning: unused variable ‘d’ [-Wunused-variable] user.cpp:13:13: warning: unused variable ‘r’ [-Wunused-variable] user.cpp:13:15: warning: unused variable ‘o’ [-Wunused-variable]